Oi :)
1) There are 3 significant digits

2)
15 Mi/h = 22 ft/s
3)

4)
There are 4 significant digitis. Leter C
Graph each points:
f(x) = -13x + 1
when x = 0, y = 1
f(0) = -13(0) + 1
f(0) = 0 + 1
f(0) = 1
when x = 1, y = -14
f(1) = -13(1) + 1
f(1) = -13 + 1
f(1) = -14
when x = 2, y = -25
f(2) = -13(2) + 1
f(2) = -26 + 1
f(2) = -25
etc.
Graph each point and connect them.
The factor is x-6 since the two factors of your equation are (6x-6) and (x-6)
Thanks for the question!
f(x) = 6 (1 - x)
f(-8) = 6 (1 - (-8))
f(-8) = 6 (9)
f(-8) = 54
Hope this helps!